Heathrow stress 'equal to facing riots'

British travellers passing through Heathrow suffer higher stress levels than fighter pilots, Formula One racing drivers, parachutists and riot police. This is not an alarmist statement but the result of in-depth research my team conducted into what happens to people as they negotiate our overcrowded, understaffed flagship airport.

Having spent years measuring the physiological stress levels suffered by people who subject themselves to extreme conditions, I was shocked to find that the airport experience is putting everyday passengers' health in grave danger.

During our study, four passengers had chest monitors fitted to record increases in heart rate, pressure pads attached to their arms to monitor changes in blood pressure and sensors attached to their finger-tips to measure changes in physiological stress. The results showed that the level of stress they felt in the airport peaked at four times, but otherwise stayed at a sustained level for longer than that experienced by the riot police and others mentioned above.

Passengers are in danger of developing tachycardia (the rapid beating of the heart) that can at times prove fatal.

Within minutes of our subjects entering Terminal 4, heart rates had increased from healthy levels of about 55 beats per minute to more than 70 beats per minute. During the four hours it took to reach the aircraft, rates continued to rise, with some recording more than 200 beats a minute - up to four times the resting heart rate of a healthy human. Even athletes do not often reach these levels. Given that our travellers were young, healthy and not exerting themselves, the results show just how much psychological stress they were under. The main causes were queues, unfriendly and impatient staff, lack of information, poor air quality and inadequate facilities.

Organisations such as Disney World are adept at lowering visitors' stress levels by deliberately "under-promising" on queuing times. They put up markers saying the wait will be 20 minutes when they know it will only be 10. The result is that people's stress levels fall as they reach the front of the queue much quicker than expected. The opposite seems to be happening at airports: lack of information or misinformation only adds to the physiological burden.

As passengers passed through a series of further queues from check-in to security, blood pressure readings showed levels of hypertension more commonly found in stroke victims. Levels rose rapidly from an average of 123/81 to peaks of around 170/99.

Skin conductance (measured by sweat gland activity and skin-pore size), a reliable measure of stress, also showed a marked increase throughout the passengers' airport journey, with peaks up to 100 times higher than in the relaxed state. Furthermore, with passengers being forced to arrive at the airport much earlier to guarantee they will catch their flight, they spend more time on their feet, which, in turn, restricts the flow of blood from feet to brain, raising blood pressure.

The return journey also showed that arriving can be as stressful as departing.

Queues of more than an hour and a half at understaffed passport desks resulted in sharp increases in heart rate and soaring blood pressure levels.

There are ways of avoiding or reducing stress, such as flying from regional airports or smaller London airports or avoiding peak times. But these options are not open to all of us. Thus, in our efforts to escape the stresses of everyday life by going on holiday, we are actually adding to them and harming our health.

Dr David Lewis is a director of research at Neuroco, an international market research organisation. His study was carried out last month for the airline Silverjet.